SOLUTION: Use the Empirical Rule to answer each question. During 1 week an overnight delivery company found that the weights of its parcels were normally distributed, with a mean of 16 ou

Algebra ->  Probability-and-statistics -> SOLUTION: Use the Empirical Rule to answer each question. During 1 week an overnight delivery company found that the weights of its parcels were normally distributed, with a mean of 16 ou      Log On


   

Question 1171528: Use the Empirical Rule to answer each question.
During 1 week an overnight delivery company found that the weights of its parcels were normally distributed, with a mean of 16 ounces and a standard deviation of 4 ounces.
(a) What percent of the parcels weighed between 8 ounces and 20 ounces? (Round your answer to one decimal place.)


(b) What percent of the parcels weighed more than 28 ounces? (Round your answer to two decimal places.)
Answer by Boreal(15235) About Me  (Show Source):
You can put this solution on YOUR website!
a This is between -2 SD and +1SD
47.5% of the curve left of the mean from -2SD to 0.
34% of the curve to the right of the mean from the mean to +1SD
81.5%.
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more than 28 ounces is more than 3 SD, and the probability is 0.00135 or 0.14% to two decimal places.